‘Self-interest has its uses, but when a substantial swath of the population can't afford to rent a rabbit hutch, it has to have limits.' Photograph: Murdo Macleod

There's nothing like a browse through the House of Commons register of members' interests to be reminded just what a powerfully motivating force self-interest is. There's the small matter of the survival of the species, of course, and the urge for parents to nurture their children; but spend even a short time contemplating the financial interests of our elected MPs and you'll be forced to reckon with an even greater force of nature: the "property portfolio".

Because there's a glaring omission from any discussion of a property market so distorted and unequal that a report published this week showed a third of the country is effectively off limits to families on an income of less than £22,000. (Not off limits in the sense of buying, you understand; that's been the case for years. Off limits even for renting.) And of the fact that this same property market – in terms of its legislative oversight, financial regulation and taxable structure – is overseen by a parliament in which a third of MPs are buy-to-let landlords.

That isn't to say that they own more than one property. The vast majority of MPs own more than one property – they generally have their constituency home and their London home, one or other of which has been kitted out with the John Lewis list as paid for by us; just as, until the expenses scandal of 2009, we also generously underwrote the interest payments on their second mortgages.

But they don't have to declare those. No, this is the 200-odd MPs who own one, two, or – in the case of James Clappison, the Conservative member for Hertsmere – 26 other properties (he also owns 27 acres of farmland and a cricket pitch, but let's not get bogged down in the detail).

Actually, why not have some detail. There's just so much of it. From Caroline Spelman, MP for Meriden in the West Midlands, whose portfolio encompasses property in Bath, London, the West Midlands and Portugal, to Mark Prisk, the housing minister who said the report was "alarmist" and "factually flawed" and who just happens to own a "part share in a commercial property in Cornwall from which rental income is derived". Or Bob Blackman, MP for Harrow East, with his six buy-to-let properties in Welwyn Garden City (which casts, let's be generous, an interesting light on a question he tabled to Grant Shapps, then housing minister and MP for Welwyn Garden City, about local authorities' duties towards the homeless).

There's Mike Freer, MP for Finchley, whose pastoral support for his constituents involves renting out two properties to them (on top of his other properties in south-west France and Dumfriesshire, obviously); whereas Jake Berry, MP for Rossendale and Darwen, has taken the (possibly more sensible) approach of keeping his speculating activities off-patch by buying commercial property and a flat in Liverpool, and two houses in North Wales.

But this is just plucking at straws. Really, you could take any name at random. Or at least one in three names at random. And not just Tories. Even that nice David Lammy has a rental property in his native Tottenham, though admittedly that's not got much on Paul Uppal, MP for Wolverhampton South West, a shareholder in his family's real estate company, Pinehurst Securities, which a quick glance at Companies House shows has assets of £2,355,021. Or David Tredinnick, whose is worth £4,407,845. Robert Goodwill, MP for Scarborough and Whitby, has the kind of "diversified" portfolio on which an asset manager would look and nod approvingly: a farm, three industrial units, four rented houses in Teesside, a development property in Yorkshire "which is under renovation with a view to letting", and of course a flat in London.

But then there are about 100 MPs who rent out a flat in London. Who doesn't have an extra flat in London they rent out and then write off the interest payments on it against tax? Oh yes, that's right, the 49% of people in the capital who rent, paying an amount which in 23 out of 32 boroughs comes to more than 50% of their income.

It's absurd to say that this is a parliament that represents working people. It's a parliament that increasingly represents the interests of the landed classes. Because make no mistake, that's what buy-to-let landlords are. And income inequality in this country is now largely a question of property inequality.

Having rented for years, I'd always assumed the fact that I haemorrhaged money into my landlords' bank accounts was a result of my financial incompetence, apathy towards traditional bourgeois values, lack of job security, moral turpitude, inability to mate with a solvent male, and so on. It's only now I've leaped over to the other side that I've discovered a tax regime which positively encourages owner-occupiers to leverage their properties, raise new mortgages and write off the interest payments against tax on rental income. And in an age of pension meltdown, short-term contracts and workforce casualisation, many feel they can't afford not to.

But that's what governments are for, after all. To work on the big picture. To consider the interests of an increasingly impoverished rising generation as well as their own; the needs of families in places like Warwick – another "affordability black spot" named in the report – who don't happen to have the resources of, say, local MP Nahdim Zawawi, lucky enough to own "residential property and 31 acres of land in Warwickshire with stables run as a livery yard", as well as the obligatory "residential buy-to-let property in London, divided into three flats". Or Richard Fuller, another local MP with properties in Warwick and, give him credit for branching out, New York.

Self-interest has its uses, but in a country where a substantial swath of the population can't even afford to rent a rabbit hutch – or the cheapest two-bedroom flat on the market, as defined by the Resolution Foundation – it has to have limits. Buy-to-let isn't actually a force of nature, it's a result of political and financial arrangements that can and should be changed.